Works fine in our deployment.

1.21.0 client now broken against our deployment.

Breakage occured with upgrade from 1.20 to 1.21

Server version: 1.17.0

koji -d moshimoshi

2020-04-27 14:15:54,072 [DEBUG] koji: Opening new requests session
2020-04-27 14:15:54,073 [DEBUG] koji: Opening new requests session
2020-04-27 14:15:54,102 [DEBUG] koji: Opening new requests session
2020-04-27 14:15:54,103 [DEBUG] koji: gssapi auth failed: MutualAuthenticationError: Unable to authenticate <Response [200]>

Traceback (most recent call last):
  File "/usr/bin/koji", line 335, in <module>
    rv = locals()[command].__call__(options, session, args)
  File "/usr/lib/python2.7/site-packages/koji_cli/commands.py", line 7389, in handle_moshimoshi
    activate_session(session, options)
  File "/usr/lib/python2.7/site-packages/koji_cli/lib.py", line 700, in activate_session
    session.gssapi_login(proxyuser=runas)
  File "/usr/lib/python2.7/site-packages/koji/__init__.py", line 2572, in gssapi_login
    raise AuthError('unable to obtain a session')
koji.AuthError: unable to obtain a session

Edit not -1 as older server version.

Likely the krb_deprecation - https://pagure.io/koji/pull-request/1992

Ignore previous comment , it is only a warning.

Server side error is:

[Mon Apr 27 14:22:46.061394 2020] [:error] [pid 3673303]     raise koji.AuthError('could not verify client: %s' % context.environ.get('SSL_CLIENT_VERIFY'))
[Mon Apr 27 14:22:46.061397 2020] [:error] [pid 3673303] AuthError: could not verify client: NONE

@stevetraylen Could you file a https://pagure.io/koji/issues ticket on this?

I am not sure what level of compatibility koji promises between client and server (likely that should be documented) and they might also be able to see some way to make this work for you (but I shouldn't speak for them).

Error from me , our server version is 1.19.1-5.el7 where the error is occuring.

Will open a ticket.

https://pagure.io/koji/issue/2201 opened.